This invention relates to the formation of an inlaid optical material for shaping a beam of light within a device substrate.
Microelectromechanical systems (MEMS) are devices often having moveable components which are manufactured using lithographic fabrication processes developed for producing semiconductor electronic devices. Because the manufacturing processes are lithographic, MEMS devices may be made in very small sizes, and in large quantities. MEMS techniques have been used to manufacture a wide variety of sensors and actuators, such as accelerometers and electrostatic cantilevers.
MEMS techniques have also been used to manufacture movable actuators of small size, generally using an electrostatic, piezoelectric or less commonly, electromagnetic actuation means to activate a movable member. MEMS devices often make use of silicon-on-insulator (SOI) wafers, which are a relatively thick silicon “handle” wafer with a thin silicon dioxide insulating layer, followed by a relatively thin silicon “device” layer. In the MEMS devices, a thin movable member may be formed in the silicon device layer, and a cavity is created adjacent to the thin beam, typically by etching the thin silicon dioxide layer below it to release the movable member.
A number of MEMS devices use or manipulate light, for example, mirrors, electrooptical transducers, infrared emitters and receivers and spectrum analyzers. In a MEMS display or projector, the movable member may be used to adjust the position of one of many optical elements, such as a tiltable mirror. Such devices typically employ also macroscopic optical elements disposed in space around the MEMS device, to shape the characteristics of the emitted or received light. The inclusion of these elements greatly adds to the overall volume taken up by the systems, increasing its cost and rendering it vulnerable to shock and vibration. For at least these reasons, MEMS based optical systems are not generally mounted on moving systems, such as vehicles, or weapons systems such as missiles or munitions, or in medical devices such as catheter-based surgical or imaging systems.